That's because the Swiss are regarded as honorary EU citizens!

There are two lines at UK passport control - the "fast track" one for citizens of the EU, the EEA and Switzerland, and the "slow" one for everybody else.

Very confusing, and I know that FAs gets this wrong on a regular basis. "Ladies and gentlemen, we are now distributing landing cards and you have to fill one in if you are not a citizen of a member state of the EU". WRONG! If you are Norwegian, Icelandic, Swiss or a citizen of Liechtenstein you don't have to fill one in either, and you use the EU line to go through passport control